Data strobe encoding is an encoding scheme used in digital circuits, for example, double data rate (hereinafter, DDR) synchronous dynamic random access memory (hereinafter, SDRAM), for transmitting/receiving data. The data strobe encoding involves two signals, that is, a data signal (DQ) and a strobe signal (DQS). In short, the strobe signal (DQS) is utilized to synchronize the data signal (DQ) under the circumstance that a phase difference between the strobe signal (DQS) and the data signal (DQ) is maintained.
Both the data signal (DQ) and the strobe signal (DQS) are clock-based signals, and different phases of the data strobe encoding rely on multi-phase memory-clock signals. In a conventional transceiver architecture, a phase-locked loop (hereinafter, PLL) clock generator for generating multi-phase memory-clock signals is the source of all necessary phase clocks. As wiring lengths of the phase signals provided to the data/strobe reception/transmission path are different, the accuracy of the phase relationships cannot be guaranteed. Moreover, in a real operation environment, the process, voltage, and temperature (hereinafter, PVT) variation may cause the changes of the multi-phase memory-clock signals.
In other words, the relationships between phases of the data signal (DQ) and the strobe signal (DQS) may distort, and this may degrade performance and data accuracy.